I found something that could solve this image issue.
In line 308 of the file: ec_js.class.php of the plugin (it′s in the folder)
You′ll see the following:
jQuery("img").attr("src", arguments[i]);
Replace it with
jQuery("#calendar_wrap img").attr("src", arguments[i]);
Added the wrapper ID (“#calendar_wrap”) so it only preloades images inside the calendar container.
No problems until now.
Hope this works for you.
Cheers from Argentina!
ben